Organization of the Body and the Nervous System

1. Organization of the Body and the Nervous System Chapter 31

2. Organization of the Human Body • 1. Cells • smallest unit still considered to be living • all living things are composed of cells • 100 trillion cells in an adult • (ex) nerve cells, muscle cells, blood cells, etc…

3. Organization of the Human Body • 2. Tissues = • groups of similar cells with one function • Muscle Cells Muscle Tissue • (ex) nerve tissue, muscle tissue, etc…

4. Organization of the Human Body • 3. Organs = • groups of tissues that perform one function • Muscle Tissue The Heart • (ex) eye, kidney, lung, intestine, stomach

5. Organization of the Human Body • 4. Organ Systems • a group of organs with one function • The Heart and Blood Vessels Circulatory System • 11 major body systems • Nervous, Endocrine, Circulatory, Respiratory, Digestive, Excretory, Immune, Reproductive, Skeletal, Muscular, Integumentary

6. Homeostasis • “keeping things in balance” • the process by which organisms keep internal conditions relatively constant despite changes in external environment • (ex) maintaining body temperature

7. Nervous System Function • Controls and coordinates the functions of the body • respond to external and internal stimuli • Control Center and Telephone Lines

8. Nerve Cells • Neurons: carry electrical signals (impulses) throughout the body • 3 Types of Neurons: • Sensory Neurons = carry impulses from sense organ to brain • Motor Neurons = carry impulses from the brain to muscles • Interneurons = connect sensory neurons and motor neurons and carry impulses between them

9. 3 Parts of the Neuron • 1. Cell Body: collects the messages • 2.Dendrites: carries the message to the cell body • 3.Axon: carries the message away from the cell body

10. Nerve Tissue • Nerve Tissue = bunch of Neurons • Impulse = the electrical message being passed from one neuron to another (telephone game)

11. Nerve Tissue • Myelin = insulation around neuron, makes the impulse travel faster • Synapse = where the impulse jumps from one neuron to the next

12. Divisions of the Nervous System • Central Nervous System • control center • relays messages, processes information, and analyzes information • Organs = brain and spinal cord

13. Divisions of the Nervous System • Peripheral Nervous System • receives information from the environment and • relays commands to the organs and glands • sensory and motor divisions • all nerves not associated with spinal cord

14. Nervous System Organs • Brain • 100 billion cells = lots of energy • control center • 3 regions: • Cerebrum = learning, intelligence • Cerebellum = muscle movement • Brain Stem = breathing, heart rate, swallowing

15. Nervous System Organs • Spinal Cord • link between your brain and the rest of the body • used for support and protection in vertebrates • Surrounded in spinal fluid

16. Nervous System Organs • Peripheral Nervous System • the nerves that branch from the spinal cord • ability to move

17. Somatic Nervous System • Regulates activities that are under conscious control • movement of skeletal muscles • response to pain, temperature, reflexes

18. Autonomic Nervous System • Regulates activities that are automatic or involuntary • speeding up of heart beat and blood flow during exercise • digestive processes

19. Diseases and Drug Abuse Chapter 31

20. Spinal Injuries • Head, neck and back injuries • Falling from 1.5x’s your height • Moving vehicle/animal accidents • results in brain damage, paralysis, loss of body control

21. Alzheimer’s Disease • Loss of memory/dementia damage to cerebrum (memory) • Caused by a loss of cells (swiss cheese) or neurons tangled (knots) • no cure • affects 50% of people over 85 yrs old

22. Meningitis • Infection of the fluid surrounding the brain and spinal cord • bacterial or viral (more sever if bacterial) • spreads easily from person to person (schools/dorms) • vaccination is available

23. Parkinson’s Disease • Damage to neurons in the cerebellum • loss of muscle control (shaking) • caused by genetics (inherited), use of illegal drugs, or extreme head injury • Michael J Fox, Muhammad Ali

24. West Nile Virus • Virus causes encephalitis (swelling of the brain) • headaches, fever, coma, death • spread by mosquitoes

25. Drugs • Any substance, other than food, that changes the structure of function of the body • positive and negative effects • all are harmful if used improperly

26. Drugs that Affect the Nervous System • Most drugs affect the synapse region • damaged synapse = messages can’t travel from neuron to neuron • body is unable to respond to environment

27. Stimulants • increases the release of neurotransmitters at synapses in the brain • increase heart rate, blood pressure, breathing rate • Result = High (energy/happy) then Low (tired/unhappy) • Long Term = heart problems, depression hallucinations • Examples = amphetamines, cocaine, nicotine, caffeine

28. Depressants • Enhance the effects of neurotransmitters, decrease the rate of brain function • slow heart and breathing rate, lower blood pressure, relax muscles • easily addicted, fatal when mixed • examples = tranquilizers, alcohol, barbiturates

29. Cocaine • Causes an increase in the release of dopamine from the brain • Dopamine causes intense feeling of pleasure or satisfaction • After cocaine wears off, dopamine levels are low = depression, cravings • highly addictive, increase heart and blood pressure, permanent heart damage, loss of control

30. Opiates • Pain-killing drugs from the center of opium poppies • mimic endorphins in the brain and help you to overcome pain • body gets used to drug (lowers endorphin levels) • Stop taking = low endorphin levels = pain, sickness • Examples = codeine, morphine, heroin

31. Marijuana • Most widely abused illegal drug • contains THC (tetrahydrocannabinol) • THC causes temporary euphoria or disorientation • Very bad for lungs (no filter) • Long term effects= loss of memory and ability to concentrate, lower levels of testosterone

32. Alcohol • Depressant which slows the rate at which the CNS functions • slows down reflexes, disrupts coordination, and impairs judgement • 40% of deadly car accidents • 1/3 of homicides • $150 billion per year • Fetal Alcohol Syndrome (50,000/year) • Liver Failure

33. http://www.montanameth.org/ Methamphetamine • Highly addictive synthetic stimulant • More addictive than heroin • Meth is sometimes referred to as "Speed," "Chalk," "Ice," "Crystal," "Glass," "Crank," "Yaba," "Fire," Tina," and "Tweak." • Symptoms: Brain damage, respiratory problems, irregular heartbeat, irreversible damage to blood vessels in the brain, strokes, heart attacks, kidney damage, cardiovascular collapse, and death. • In Montana alone • 52% of children in foster care are there due to Meth. • 50% of adults in prison are there due to Meth-releated crime. • 20% of adults in treatment are there for Meth addiction.

34. The Senses Chapter 35 -4

35. Sensory Receptors • Neurons that react directly to stimuli in the environment • Concentrated in sense organs • 5 Categories • pain receptors: respond to damaged cells • thermoreceptors: variations in temperature • mechanoreceptors: touch, pressure, sound, motion • chemoreceptors: chemicals in the enviro • photoreceptors: sensitive to light

36. Responding to Stimuli 1. Sense organ detects stimuli 2. Neurons carry impulse 3. Brain decides how to respond 4. Neurons carry message away from brain to the part of the body that will respond

37. Vision • Sense Organ = eyes • photoreceptors convert light energy into nerve impulses that are carried to the brain • the brain forms one image and interprets the image

38. Hearing • Sensory Organ = Ear • Mechanoreceptors convert sound waves into nerve impulses that are carried to the brain • Brain interprets language and distinguishes between pitch and loudness

39. Smell • Sense Organ = nose • Chemoreceptors in the nose detect chemicals and convert them into nerve impulses that are carried to the brain • Brain interprets smells (good, bad, what is it?) • Can’t smell when stuffed up

40. Taste • Sense Organs = Nose and Taste Buds • Chemoreceptors in the nose detect chemicals from the food and turn it into an impulse • the brain determines what you are eating and your opinion • chemoreceptors in taste buds detect different tastes (sweet, salty, sour, bitter)

41. Touch • Sense Organ = skin • 3 different receptors to detect temperature, touch, and pain • Concentrated in areas (fingers, toes, face)